Fuse mechanism



Aug. 11, 1925. 1,549,652

L. N. CRICHTON FUSE MECHANRSM Filed Oct; 11. 1922 2 Sheets-Sheet 1 INVENTOR WITNESTSES: I Les/1 6M Cr/c/zfoq.

. I BY ATTORNEY Aug. 11, 1925. 1,549,652

L. N. CRICHTON FUSE MECHANISM Filed Oct. 11'. 1922 2 Sheets-Sheet 2 WlNESS INVENTOR Les/k/MCrichfon.

I Y ATTORNEY v Patented Aug. 11, 1925.

UNITED STATES LESLIE N. CRICHTON, OF WILKINSBURG,

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

FUSE MECHANISM.

Application filed October 11, 1922. Serial No. 593,666.

To all whom it may concern:

Be it known that I, LESLIE N. CRICHTON,

a citizen of the United States, and a resident of Wilkinsburg, in the county of Alle- 6 gheny and State of Pennsylvania, have invented a new and useful Improvement in Fuse Mechanism, of which the following is a specification.

My invention relates to fuse mechanism and particularly to fuse mechanism used in high-tension circuits for protecting transformers and other equipment.

One object of my invention is to provide a high-tension expulsion fuse that serves as a combined switch and fuse and which may readily be refilled without danger to the operator.

Another object of my invention is to provide an expulsion-fuse mechanism wherein a plurality of fuses may be connected in such manner that they may be actuated to open or to closed positions simultaneously by means of a single operating lever which may be disposed at any remote point con- 25 venient for operation.

Another object of my invention is to provide an expulsion fuse that may serve as a combined switch and fuse and wherein at least one of the fuse terminals is insulated from the fuse tube to prevent creeping of the current between the conductor terminals to which the fuse is connected after the fuse is blown.

It has been found that, when fuse casings having directly-connected fuse terminals are employed on high-tension circuits, the current creeps from one terminal to another when the surface oithe f ise casing is moist, because of rain or dew gathering on the outer surface. The moisture is vaporized and an arc is formed between the terminals, resulting in severe charring of the fuse tube which is usually made of micarta or similar insulating material.

The are is destructive both to the fuse casing and to equipment connected to the fuse. An insulator is, therefore, disposed between at least one of the fuse terminals and the micarta tube. This construction provides a gap between the terminals over which the current cannot creep, the insulator being designed and proportioned to obviate'any creeping tendency of the current. When the fuse is blown, there is no creepage path betweenthe fuse contacts.

Another object of my invention is to provide a fuse mechanism, having the above characteristics, that may be detachably secured to the conductor terminals and wherein one of the conductor terminals is hinged to its support and may be actuated for movemg the fuse terminals out of engagement with one of the conductor terminals.

Another object of my invention is to provide a combined switch and expulsion fuse for connecting conductor terminals wherein one of the conductor terminals is hinged to the support, wherein both conductor terminals are insulated therefrom and wherein at least one of the fuse terminals is insulated from the fuse casing.

Another object of my invention is to provide a combined switch and expulsion fuse wherein one of the conductor terminals is hinged to its support and provided with a contact clip in which the fuse casing may be detchably secured, and wherein the fuse terminal is insulated from the fuse casing and provided with a blade adapted to enter the contact jaws of one of the conductor terminals.

A further object of my invention is to provide a combined expulsion fuse and switch that is inexpensive, which may be readily assembled in the field and which may be operated with perfect safety.

These and other objects, that will be made apparent throughout the further description of my invention, are attained by means of the apparatus hereinafter described, and

illustrated in the accompanying drawings,

wherein:

Figure 1 is an elevational view of the expulsion fuse permanently hinged to a conductor terminal to constitute a combined switch and fuse;

Fig. 2 is a plan view of the switch mechanism shown in Fig. 1;

Fig. 3 is an elevational view of an. expulsion fuse that is detachably secured to a hinged conductor terminal;

Fig. 4 is an elevational view of an expulsion fuse embodying features of my invention, that is adapted to be detaohably connected tothe conductor terminals;

Fig. 5 is an elevational view of a double expulsion fuse embodying features of my invention and which is connected in series;

Fig. 6 is a plan view of the apparatus shown in Fig. 5;

Fig. 7 is an elevational view of a transformer installation, showing combined expulsion fuses and switches embodying my invention connected thereto, and

Fig. 8 is a side elevational view of the mechanism shown in Fig. 7. 1

Referring to the drawings and particularly to Figs. 1 and 2, the combined switch and fuse mechanism includes a pair of insulators 9, composed of material that is impervious to moisture, that are secured to a support member 11. Conductor terminals 12 and 13 are, mounted upon the insulators 9, the former being provided' with yielding switch-jaw contact members 14 and the latter being provided with a hinged I member 15.

The expulsion fuse comprises a tubular casing 16 that is made of micarta, or similar insulating material, and is provided, at one end, with a clamp 17 that engages the outer surface of the tube and which carries an insulator 18 having a contact blade 19 embedded therein.

The blade 19 is provided with a terminal member 21 having a wing nut 22 for attaching the exposed end of a fusible member 23 thereto. The fusible member extends through the casing 16 and projects from the lower end thereof and is secured to the hinged terminal 15 by means of a terminal screw 24. The lower end of thecasing is provided with a hinge member 25 that is pivoted to the hinge member 15.

From the foregoing, it will be apparent that the expulsion fuse constitutes a switch having an insulated contact blade 19 that may be moved into, and out of, engagement with the contact-jaw members 14. It will be seen that the insulator 18 prevents any tendency of the current to creep from the terminal 12 to the terminal 13, even though the outer surface of the casing 16 is covered with moisture.

When it is desired to renew the fusible member, the casing 16 is first moved outwardly by means of a hook stick usually employed for operating switches of this character. A new fusible member may be safely inserted and connected to the terminals 13 and the blade 19.

Referring to Fig. 3, a modified construction is shown wherein a conductor terminal 26 is mounted upon an insulator 27, composed of material that is impervious-to moisture, that is carried upon a bent arm 28. The arm 28 is mounted upon an operating rod 29 that is square in cross section.

Whenthe rod is rotated, the arm 28 is moyed angularly. It will be seen that any desired number of arms 28 may be provided upon the rod 29, as shown in Figs. 7 and 8, for the purpose of simultaneously ma nipulating expulsion fuses mounted upon each arm. The construction of the expulsion fuse, illustrated in Figs. 3, 7 and 8, is like that shown in Fig. 1 except that the lower fuse terminal is of modified construction.

The lower fuse terminal 31 comprises a contact member that is secured to the lower end of the casing 16 and is provided with a terminal screw 32 for attaching the lower end of the fuse member 23 thereto. The conductor terminal 26 is provided with yielding contact-j aw members 33 for receiving the fuse contact member 32. The contact between the members 32 and 33 is of such rigidity that the outward movement of the insulator arm 28 causes the fuse casing 16 to be moved therewith for separating the blade member 19 from the contact-jaw members 14.

In order to renew the fusible member, the fuse is first moved into open position by r0.- tating the rod 29. The rod is actuated by a lever 34 that is connected to a vertical rod 35 which extends to a convenient point for operation. After the casing has been moved to open position, it may be detached bodily from the contact-jaw members 33 for facilitating the renewal of the fuse.

Referring to Fig. 4, a further modification of the fuse mechanism is shown wherein the expulsion fuse 16 is like that shown in Fig. 3, except that the contact member 32 is disposed adjacent the lower end of the tube and is adapted to be inserted between the contact jaws 33 that are carried by an insulator 27 which is permanently secured to the support 11 by means of an arm 36.

In Figs. 5 and 6, I have shown a modified construction in which a pair of fuse tubes, similar to the tube illustrated in Fig. 4. have the lower fuse contacts mounted upon a rotatable member 37. The member 37 comprises a metal tube or bar that is mounted for rotation in the horizontal position upon a bracket 38 that is secured to a support 39 by means of an insulator 41.

The lower fuse terminals 42 of the fuse casing 16 are attached to the conductive bar 37 and to the lower end of the casings. The bar is provided with an operating lever 43 that is actuated by a vertical insulated operating rod 44. The construction of the upper end of the expulsion fuse mechanism is like that illustrated in Fig. 4 and, conseguently, the contact blades 19 are disengaged rom the contact-jaw members 14 when the rod 37 is rotated.

It will be seen that, because of the conductor element or rod 37 which onnects the lower fuse terminals 42, the fuses are connected in series and afiord double protection to the circuit.

Referring to Figs. 7 and 8, a transformer installation is shown wherein fuse mechanism, such as is illustrated in Fig. 3, is connected to the transformers by means of spring choke coils 4.5 which permit of limited movement of the conductors 46 that are connected to the terminals 26 on the expulsion fuses.

As illustrated, three fuses are employed, and the conductor terminals 26 are connected to the hinged insulator arms 28 which are rotated by means of the lever 34 and the operating rod 35. An operating handle 4:7 is pivoted to one of the supporting masts 48 to cause the switches to be moved simultaneously to open position when the handle is moved upwardly. I

In the construction illustrated in Figs. 7 and 8, the support member 11 for each fuse device is secured to the horizontal mast arms 49 that are secured to the masts 48.

While I have described and illustrated but four embodiments of my invention, it will be apparent to those skilled in the art that various changes, modifications, substitutions, additions and omissions may be made therein without departing from the spirit and scope of my invention, as set forth in the appended claims.

I claim as my invention:

1. The combination with an explusion fuse tube and a fusible member, of a terminal for receiving the fusible member and an insulator for attaching the terminal to the fuse tube.

2. The combination with a pair of conductor terminals for supporting a fuse tube and to which the fusible member is electrically connected, of a means for insulating the tube from at least one of the said terminals.

3. An explusion fuse comprising a fuse tube, a fusible member, fuse terminals mounted on the tube, conductor terminals and means for insulating the tube from at least one of the conductor terminals.

4;. The combination with an explusion fuse tube and a fusible member, of a terminal for receiving the fusible member and an insulator for attaching the terminal to the fuse tube and for supporting the terminal. in spaced relation to the tube.

5. The combination with an explusion fuse tube having an open end and a fuse element within the tube and projecting from the end of the tube, of a terminal for the exposed end of-the fuse adapted to be connected to a feed terminal and an insulator for attaching the fuse terminal to the fuse tube.

6. A high-tension explusion fuse comprising a tube member, a fusible member, and

terminals for the fusible member mounted exteriorly of the tube and in spaced relation and adapted to be connected to feed terminals, at least one of the fuse terminal members being insulated from the fuse tube.

7. The combination in a fused" switch comprising a fuse tube having fuse termi nals for engaging the terminals of the switch, of an insulator between the fuse tube and one of the fuse terminals.

8. A fused switch comprising a pair of spaced terminal members, a fuse tube having a pair of fuse terminal members thereon, one of Which is pivoted to one of the said spaced terminal members and the other adapted to detachably engage the other spaced terminal member, and an insulator for connecting one of the fuse terminal members to the fuse tube.

9. A fuse device comprising a su port, a pair of conductor terminals secure to the support, one of the said terminals being hinged thereto, and a fuse device having a pair of fuse terminals thereon, one of which is insulated from the said device for conductively engaging the said conductor terminals.

10. A fuse device comprising a support, a pair of insulating supports mounted thereon, one of which is hinged to the support, conductor terminals mounted on the insulating supports, and a fuse device having a pair of fuse terminals thereon for, conductively engaging the said conductor terminals, one of the said terminals being insulated from the fuse device.

11. The combination in a fused switch comprising a fuse tube having fuse terminals for engaging the terminals of the switch, of an insulator impervious to m0isture between the fuse tube and one of thefuse terminals.

In testimony whereof, I have hereunto subscribed my name this 20th day of September 1922.

LESLIE N. CRICHTON. 

